“There was certainly a high potential for heavy rain if these storms did move south and they did.”

Hull said winds blowing off the lake fueled the storm as it hovered over North York before moving toward the south end of the city.

Geoff Coulson, a meteorologist with Environment Canada, told Global News on Wednesday the special weather statement issued by the weather agency, which didn’t go out till after 9 p.m., was slightly delayed due to a myriad of factors.

“It’s size, its localized nature and the speed with which it intensified all played into the fact that it took a little longer to get that special weather statement out than we would normally see like with other events,” he said.

Coulson said the statement went out when it became “apparent that the storm cell had slowed down even further, or was almost stationary over the city of Toronto and there was going to be a possibility of some huge rainfall amounts.”

He said storm cells like the one Tuesday night — localized and slow moving — continues to be “one of the most challenging types of weather phenomenon in our forecast.”

“This is a challenge, not only being faced by forecasters in Canada, but in the United States, in Europe,” Coulson said. “The nature of the beast when it comes to trying to track these localized or slow-moving events and all the ingredients that may come together to create them is not something that’s still very well understood.”

He said the agency will take the data from this event and learn from it.

WATCH: Toronto residents battle flooded streets after deluge of rain

According to a preliminary weather summary issued by Environment Canada on Wednesday after 12:30 a.m., the heaviest rain hit Highways 400 and 401, the area near Allen Road, the downtown core and the Toronto Islands.

The weather agency said approximately 50 to 75 millimetres of rain fell in the span of two to three hours across the area. Localized areas may have experienced higher amounts of rainfall.

“Note that most other areas across Toronto received much less than 20 millimetres of rain, thus showing the very localized nature of the heavy showers,” the statement said.

Hull noted the normal rainfall amount for the entire month of August in Toronto is 78.1 millimetres.

“ basically more than a month’s rain … so you can understand how that could lead to significant flooding,” he said.

All customers affected by the @HydroOne loss of power supply in North York have been restored. If your home or building is still without power, please call our dispatch centre at 416.542.8000 and press 1.

At 10:15 p.m. on Tuesday, Toronto Hydro said approximately 16,000 customers lost power due to a loss of supply from Hydro One.

But most of the outages were cleared by 12:30 a.m. on Wednesday.

That loss of power, combined with the volume of water, meant emergency crews had to rescue people trapped in elevators.

At a commercial building near Rockcliffe Boulevard and Alliance Avenue, southeast of Jane Street and Eglinton Avenue West, Toronto police said two people called 911 after 10:50 p.m. on Tuesday to report that they were trapped in an elevator in the basement as water began to fill it.

“As the water was rising very, very quickly, they only had about a foot of airspace left inside the elevator and it was completely closed, so officers pried the elevator open and rescued the two men,” spokesperson Katrina Arrogante told Global News.

RESCUE UPDATE: @TPSKatrina tells me officers were called to this commercial building at 10:52 p.m. After police arrived, officers were able to pry the doors open about six minutes later and free the people inside. She said the phone reception was weak too. https://t.co/unZG3IV4Mp

She said the officers had to find a crowbar and swim through the basement to access the elevator.

Meanwhile, emergency crews were called to multiple scenes with vehicles trapped on roads and surrounded by water.

Three vehicles were stuck on Wilson Street near Dubray Avenue, east of Keele Street. However, the occupants were able to leave safely.

In downtown Toronto, the police marine unit was called in to help several people stuck in four vehicles near Lower Simcoe Street and Bremner Boulevard. There were no reports of injuries.

Residents in the downtown core and in midtown Toronto posted photos and video showing flooding on local roads.

The heavy rains the closure of several roads, including parts of the Don Valley Parkway and Lake Shore Boulevard West.

Toronto Fire Services (TFS) said water is approximately a metre deep on some roads and that crews are receiving reports of basement flooding.

TFS Chief Matthew Pegg said as of 11 p.m., firefighters were responding to approximately 98 active calls.

Residents wanting to report downed hydro lines and flooding damage are encouraged to contact the City of Toronto’s 311 line.

If you're waking up to a flooded basement, please remember that electricity and water don't mix. Don't use flooded appliances, outlets, switches or breaker panels until they have been checked by a qualified electrician. If your basement is flooded, power needs to be disconnected.

Public advisory:Due to the weather we are having and the amount of rain that has fallen throughout the city. Fire Services and Police Service lines are busy from flooding calls. Please only call 911 for emergencies. Thank you.^ka